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Nikolaos P Polyzos - One of the best experts on this subject based on the ideXlab platform.

  • cumulative live birth rates and number of oocytes retrieved in women of advanced age a single centre analysis including 4500 women 38 years old
    Human Reproduction, 2018
    Co-Authors: Marta Devesa, I Rodriguez, Buenaventura Coroleu, Francisca Martinez, Nikolaos P Polyzos
    Abstract:

    STUDY QUESTION: Is there any relationship between the number of oocytes retrieved and cumulative live birth rates (CLBRs) in women of advanced age? SUMMARY ANSWER: CLBRs increase with the number of oocytes retrieved in women of advanced reproductive age up to 41 years old, the added value is minimal in women more than 41 years and futile in women 44 years or older. WHAT IS KNOWN ALREADY: CLBR is actually the most relevant outcome of IVF from patients' perspective. There are several studies that have analysed CLBR's but some of them have included several stimulation cycles, others have not included the frozen embryo transfers (FETs) in their analysis and none has focused on women of advanced reproductive age. We aimed to assess CLBR in women ≥38 years after a single stimulation cycle plus the subsequent frozen embryo transfers. STUDY DESIGN, SIZE, DURATION: This is a retrospective analysis carried out in a University-affiliated tertiary centre between January 2000 and December 2013. Overall, 4570 infertile women aged ≥38 years who underwent their first cycle in our centre were included. PARTICIPANT/MATERIALS, SETTING, METHODS: Patients were categorized in four age-groups: 38-39 years (G1 = 1875 cycles), 40-41 years (G2 = 1380 cycles), 42-43 years (G3 = 833 cycles) and ≥44 years (G4 = 482 cycles). CLBR's were evaluated by adding the pregnancies and live births achieved in the FET's to the ones obtained in the fresh cycle. In order to find out the actual effect of the number of oocytes retrieved in these patients, a predictive model of CLBR according to age and oocyte yield was built. MAIN RESULTS AND THE ROLE OF CHANCE: CLBRs significantly decrease with increasing age among women ≥38 years of age, with the most prominent and clinically relevant decline observed at 42-43 years old, and clear evidence for futility in women aged ≥44 years (25.9% at 38-39 years, 16.4% at 40-41 years, 7% at 42-43 years and 1.2% from 44 years onwards). The higher the number of oocytes retrieved, the higher the CLBR; however, this is more evident up to 41 years old and no clear benefit is observed from 44 years and beyond. LIMITATIONS, REASONS FOR CAUTION: Limitations are related to the retrospective nature of the study; however, no significant differences were observed in the treatment protocols used. Other potential limitations could be the fact that embryo cryopreservation was carried out with slow freezing in 80% of cases and that a small proportion of patients still have frozen embryos; nevertheless, we do not expect a relevant impact of these issues as slow freezing showed excellent results that did not differ significantly compared to vitrification and, on the other hand, the extra benefit coming from the FETs was very limited. WIDER IMPLICATIONS OF THE FINDINGS: The number of oocytes retrieved is significantly associated with CLBR also in women of advanced reproductive age. However, the added benefit appears to be restricted mainly in women up to 41 years old. Women over 43 do not experience any benefit in CLBR irrespective of the number of oocytes retrieved, and thus should be discouraged from doing an IVF cycle with their own oocytes; for the other age-groups, recommendations should be given considering the age and the expected ovarian response. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: NA.

Jin Yang - One of the best experts on this subject based on the ideXlab platform.

  • 0d 2d and 3d metal phosphonates assembled from a new 2 carboxybiphenyl 4 ylmethylphosphonic acid syntheses topological structures and photoluminescent properties
    CrystEngComm, 2012
    Co-Authors: Jin Yang
    Abstract:

    A series of metal phosphonates, namely, [Cu(HL)(H2O)] (1), [Cu5(L)2(OH)4]·H2O (2), [Zn3(L)2(H2O)] (3), [Zn3(L)2(phen)2(H2O)2] (4), [Cd3(L)2(H2O)2] (5), [Cd2(L)(OH)(H2O)1.5] (6), and [Cd(HL)(phen)2]·2.5H2O (7), where H3L = 2′-carboxybiphenyl-4-ylmethylphosphonic acid, and phen = 1,10-phenanthroline, have been synthesized under hydrothermal conditions. Compound 1 exhibits a 2D layer structure with the 4-connected (42·64) topology. Compound 2 shows a 2D (3,10)-connected (32·6)(38·48·512·69·74·84) topology. Compound 3 displays a 2D (3,6)-connected (42·6)2(47·66·82) topology. Compound 4 is a 3D framework with the (42·6)2(47·66·82) topology. Compound 5 shows a 2D (4,6)-connected (44·62)(46)(410·65) topology. Compound 6 exhibits a 2D (3,6)-connected (42·6)(46·66·83) topology. Compound 7 displays a 0D closed loop structure. Furthermore, compounds 1, 5 and 7 are consolidated by the intramolecular O–H⋯O hydrogen bonds. All the compounds have been characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. The luminescent properties of 3–7 have also been studied.

  • 0D, 2D and 3D metal phosphonates assembled from a new 2′-carboxybiphenyl-4-ylmethylphosphonic acid: Syntheses, topological structures and photoluminescent properties
    CrystEngComm, 2012
    Co-Authors: Jian-fang Ma, Jin Yang
    Abstract:

    A series of metal phosphonates, namely, [Cu(HL)(H2O)] (1), [Cu5(L)2(OH)4]·H2O (2), [Zn3(L)2(H2O)] (3), [Zn3(L)2(phen)2(H2O)2] (4), [Cd3(L)2(H2O)2] (5), [Cd2(L)(OH)(H2O)1.5] (6), and [Cd(HL)(phen)2]·2.5H2O (7), where H3L = 2′-carboxybiphenyl-4-ylmethylphosphonic acid, and phen = 1,10-phenanthroline, have been synthesized under hydrothermal conditions. Compound 1 exhibits a 2D layer structure with the 4-connected (42·64) topology. Compound 2 shows a 2D (3,10)-connected (32·6)(38·48·512·69·74·84) topology. Compound 3 displays a 2D (3,6)-connected (42·6)2(47·66·82) topology. Compound 4 is a 3D framework with the (42·6)2(47·66·82) topology. Compound 5 shows a 2D (4,6)-connected (44·62)(46)(410·65) topology. Compound 6 exhibits a 2D (3,6)-connected (42·6)(46·66·83) topology. Compound 7 displays a 0D closed loop structure. Furthermore, compounds 1, 5 and 7 are consolidated by the intramolecular O–H⋯O hydrogen bonds. All the compounds have been characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. The luminescent properties of 3–7 have also been studied.

David A. Grant - One of the best experts on this subject based on the ideXlab platform.

  • current results of intestinal transplantation
    The Lancet, 1996
    Co-Authors: David M Grant, David A. Grant
    Abstract:

    Abstract Summary Background Intestinal transplantation is an alternative to total parenteral nutrition (TPN) for the treatment of chronic intestinal failure. To determine the current status of small-bowel transplantation, we have reviewed the world experience since 1985. Methods We built up an international registry by asking twenty-five intestinal transplantation programmes to submit standard data on their cases operated on between 1985 and June, 1995. Findings One centre (two transplantations) did not use our report form, and these cases were excluded. The remaining twenty-four programmes did 180 transplantations in 170 patients. Two-thirds of the recipients were children. The main indication (64%) was short-gut syndrome; another 13% had a tumour. Of the grafts, 38% were small-bowel with or without colon, 46% were intestine plus liver, and 16% were multivisceral. Graft/patients' survival (%) at 1 and 3 years under cyclosporin immunosuppression was, respectively: 17/57 and 11/50 for small bowel only; 44/44 and 28/28 for intestine plus liver; and 41/41 and 41/41 for multiviscera. The corresponding figures under tacrolimus were: 65/83 and 29/47; 64/66 and 38/40; and 51/59 and 37/43. 78% of the 86 survivors had stopped TPN and resumed oral nutrition. Interpretation Our approach cannot give data on long-term outcome. The short-term results of intestinal transplantation are similar to those of lung grafting. We conclude that small-bowel transplantation has become a life-saving option for patients who cannot be maintained on TPN and for those who require massive abdominal evisceration for locally aggressive tumours.

Niladri Chatteerjee - One of the best experts on this subject based on the ideXlab platform.

  • Modelling of pedestrian unsafe road crossing behavior: A comparison at a signalized and a non-signalized crosswalk
    Transportation Research Board 92nd Annual Meeting, 2013
    Co-Authors: Mariya Khatoon, Niladri Chatteerjee
    Abstract:

    Phone: +91 11 2659 1490 27 Fax: +91 -11 -2658 1005 28 Email: niladri@maths.iitd.ac.in 29 30 Word count: 31 Abstract = 246 (250 max.) 32 Body = 5527 33 Tables=4* 250 = 1000 34 Figure=1* 250 = 250 35 Total body = 7023 (7500 max.) 36 Submittal date: November 15, 2012 37 38 39 40 41 42 43 44 45 46 47 48 49 50 TRB 2013 Annual Meeting Paper revised from original submittal. 2 Khatoon, Tiwari, and Chatterjee Modelling of pedestrian unsafe road crossing behavior: A comparison at a signalized and a non-1 signalized crosswalk 2 3 ABSTRACT 4 5 Background: Many pedestrians are found to indulge in unsafe road crossing at both the signalized and 6 non-signalized crosswalks. 7 Objective: To study and compare unsafe pedestrians' crossing behaviour at a signalized and/or a non-8 signalized crosswalk. 9 Method: F and t tests are performed to observe which crosswalk has the larger mean and variance of the 10 available gap-size in the traffic flow and waiting time of pedestrians. Logistic regression models are fitted 11 to examine the pedestrians' risk and unsafe road crossing behavior at two crosswalks. 12 Results: Mean and variance of available gap size and waiting time to pedestrian at a signalized cross 13 walk is larger than a non-signalized crosswalk. At a signalized crosswalk, probability of crossing by a 14 pedestrian with the gap size less than the adequate gap size is about 98%; and at a non-signalized 15 crosswalk it is about 95%. At a signalized crosswalk only gap size parameter is significant. However, at a 16 non-signalized crosswalk other predictor parameters (such as gender of the pedestrian, whether alone or 17 in a group, type of the conflicting vehicle and traffic volume) are significant in determining the pedestrian 18 road crossing behavior. The odds of an unsafe road crossing by a pedestrian at a signalized crosswalk is 19 about 1.7 times higher than that at a non-signalized crosswalk. 20 Conclusion: Pedestrians unsafely cross roads when gaps are available within the traffic flow, at both 21 signalized and non-signalized crosswalks. Thus gap size is a significant parameter to determine the 22 pedestrians' unsafe road crossing behaviour at both crosswalks. 23 24

Richard R Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • synthesis of muramyl peptides containing meso diaminopimelic acid
    European Journal of Organic Chemistry, 2002
    Co-Authors: Niels Kubasch, Richard R Schmidt
    Abstract:

    Chain-extension of L-glutamate aldehyde 3 by means of the Wittig−Horner reaction furnished the desired C7 dicarboxylic acid derivative, which in turn, after C-C double bond hydrogenation and protecting group manipulation, afforded the 2,6-diaminopimelic acid derivatives (S,R)-9 and (S,S)-9, both with the desired orthogonal protecting group pattern. Synthesis of the muramic acid derivative 15 and attachment of an L-alanine residue furnished muramyl-L-alanine 18. The corresponding 1,6-anhydromuramic acid derivative 26 was obtained similarly. Treatment of these compounds with peptides 28−30 and with the 2,6-diaminopimelic acid containing di- and tripeptides 32a, 32b, and 35 gave the protected muramyl peptides 17, 37, 40, 42, 44, 46, and 49a and 49b, which, after deprotection, afforded the desired target molecules muramyl-L-alanine (38), muramyl-L-alanyl-D-glutamic acid (39), muramyl-L-alanyl-D-glutaminide (41), muramyl-L-alanyl-D-isoglutaminyl-L-lysine (43), muramyl-L-alanyl-D-isoglutaminyl-(2S,6R)-2,6-diaminopimelic acid (45), muramyl-L-alanylL-isoglutaminyl-(2S,6R)-2,6-diaminopimelinyl-D-alanine (47), 1,6-anhydromuramyl-L-alanyl-D-isoglutaminyl-(2S,6R)-2,6-diaminopimelic acid (50a), and 1,6-anhydromuramyl-L-alanyl-D-isoglutaminyl-(2S,6S)-2,6-diaminiopimelic acid (50b). (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)